Power equipment device with removable attachments

ABSTRACT

The disclosed technology relate to a device and system that include an outdoor power equipment power unit or cart configured to releasably couple a number of different interchangeable attachments or work implements to a common power unit, where some attachments include and/or require operator presence control, while other attachments do not include and/or require operator presence control. The outdoor power equipment power unit includes a power transfer coupling member operatively coupled to the drive shaft and configured to transfer rotational power to the associated attachment; and an operator presence actuation member operatively coupled to the operator presence control member, the operator presence actuation member configured to rotate in response to user actuation of the operator presence control member.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims benefit of U.S. Non-provisional patentapplication Ser. No. 14/620,129 filed Feb. 11, 2015, which claimsbenefit of Provisional Patent Application Ser. No. 61/938,581, filedFeb. 11, 2014, and entitled “POWER EQUIPMENT DEVICE WITH REMOVABLEATTACHMENTS”, which are herein incorporated by reference in theirentireties.

FIELD OF THE INVENTION

The disclosed technology relates generally to outdoor power equipment,and, more particularly, to outdoor power equipment that includes a powerunit or base cart that is configured to releasably couple to a varietyof outdoor power equipment attachments.

BACKGROUND OF THE INVENTION

Traditional outdoor power equipment typically has been configured as asingle-purpose machine, for example, a lawn mower, a snow thrower, ablower, a pressure washer, power generator, etc. with a dedicated engine(e.g., a conventional internal combustion engine). While users might beinterested in owning and making use of multiple pieces of powerequipment, often cost and space constraints prevent users from owning alarger number of single-purpose outdoor power equipment machines.

While efforts have been made to provide a device having a single powerunit and multiple interchangeable attachments, conventional devices lackversatility in the number of work implements that can be attached to thepower unit, as well as suffering from difficulty in attaching anddetaching the various work implements to the power unit.

BRIEF SUMMARY OF THE INVENTION

Aspects of the disclosed technology relate to a device and system thatinclude an outdoor power equipment power unit or cart configured toreleasably couple a number of different interchangeable attachments orwork implements to a common power source in a manner that is secure,safe, easy and straightforward for the user.

One aspect of the disclosed technology relates to an outdoor powerequipment power unit configured to selectively power an associatedattachment releasably coupled to the power unit. The power unit includesa frame; a handle operatively coupled to the frame; user controlsoperatively coupled to the handle, the user controls including anoperator presence control member; a power supply operatively coupled tothe frame; a generally horizontal drive shaft operatively coupled to theengine; a power transfer coupling member operatively coupled to thedrive shaft and configured to transfer rotational power to theassociated attachment; and an operator presence actuation memberoperatively coupled to the operator presence control member, theoperator presence actuation member configured to rotate in response touser actuation of the operator presence control member.

Another aspect of the disclosed technology relates to an outdoor powerequipment attachment configured to be releasably coupled to anassociated power unit. The outdoor power equipment attachment includes ahousing and a back attachment plate associated with the housing; adriven working member disposed at least partially within the housing; apower transfer coupling member configured to engage a power transfercoupling member associated with the power unit, the power transfercoupling member being operatively coupled to the driven working memberto selectively transfer motive power to the driven working member; andan operator presence actuation member configured to engage an operatorpresence actuation member associated with the power unit, the operatorpresence actuation member configured to be rotatably actuated by theoperator presence actuation member associated with the power unit; andwherein the operator presence actuation member is operatively coupled adrive engagement member configured to selectively engage the powertransfer coupling member to the driven working member to drive theworking member.

Another aspect of the disclosed technology relates to a power transfercoupling device configured to couple a base power unit to an outdoorpower equipment accessory. The power transfer coupling device includes abase; a plurality of engagement teeth extending from the base, each ofthe plurality of engagement teeth having a lower portion including apair of side walls, an outer wall, and an inner wall, and a top portionhave a pair of top walls that extend from the side walls and meet at anangle.

According to one feature, the angle formed by the top walls is greaterat the outer wall than at the inner wall.

According to one feature, the angle formed by the top walls isapproximately the same at the outer wall and at the inner wall.

Another aspect of the disclosed technology relates to a dog clutchassembly configured to rotationally transfer power from a base powerunit to an outdoor power equipment attachment releasably coupled to thebase power unit. The dog clutch assembly includes a first member, thefirst member comprising a base and a plurality of engagement teethextending from the base, each of the plurality of engagement teethhaving a lower portion including a pair of side walls, an outer wall,and an inner wall, and a top portion have a pair of top walls thatextend from the side walls and meet at an angle; and a second member,the second member comprising a base and a plurality of engagement teethextending from the base, each of the plurality of engagement teethhaving a lower portion including a pair of side walls, an outer wall,and an inner wall, and a top portion have a pair of top walls thatextend from the side walls and meet at an angle; wherein the firstmember and second member are configured to engage one another by way ofthe engagement teeth associated with the first member and the secondmember.

Another aspect of the disclosed technology relates to a power transfercoupling device configured to couple a base power unit to an outdoorpower equipment accessory. The power transfer coupling device includes abase and a plurality of engagement teeth extending from the base, eachof the plurality of engagement teeth having a lower portion including apair of side surface, an outer surface, and an inner surface, and a topportion have a pair of top surfaces that extend from the side surfacesand meet at an angle.

These and further features of the disclosed technology will be apparentwith reference to the following description and attached drawings. Inthe description and drawings, particular embodiments or aspects of thedisclosed technology have been disclosed in detail as being indicativeof some of the ways in which the principles of the disclosed technologymay be employed, but it is understood that the disclosed technology isnot limited correspondingly in scope. Rather, the disclosed technologyincludes all changes, modifications and equivalents coming within thespirit and terms of the claims appended thereto.

Features that are described and/or illustrated with respect to oneembodiment may be used in the same way or in a similar way in one ormore other embodiments and/or in combination with or instead of thefeatures of the other embodiments.

It should be emphasized that the term “comprises/comprising” when usedin this specification is taken to specify the presence of statedfeatures, integers, steps or components but does not preclude thepresence or addition of one or more other features, integers, steps,components or groups thereof.

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS

These and other features of the disclosed technology, and theiradvantages, are illustrated specifically in embodiments of the disclosedtechnology now to be described, by way of example, with reference to theaccompanying diagrammatic drawings, in which:

FIG. 1 is a diagrammatic illustration of a an outdoor power equipmentsystem with a power unit connected to a lawn mower attachment inaccordance with one aspect of the disclosed technology;

FIG. 2 is a perspective view of a an outdoor power equipment system witha power unit connected to a lawn mower attachment in accordance with oneaspect of the disclosed technology;

FIG. 3 is a front perspective view of a power unit in accordance withone aspect of the disclosed technology;

FIG. 4 is a rear perspective view of a power unit in accordance with oneaspect of the disclosed technology;

FIG. 5 is a front view of a portion of a power unit in accordance withone aspect of the disclosed technology;

FIG. 6 is an enlarged perspective view of a portion of a power unit inaccordance with one aspect of the disclosed technology;

FIG. 7 is a front view of a power unit in accordance with one aspect ofthe disclosed technology;

FIG. 8 is a side view of a power unit in accordance with one aspect ofthe disclosed technology;

FIG. 9 is a rear view of a power unit in accordance with one aspect ofthe disclosed technology;

FIG. 10 is a bottom perspective view of a power unit in accordance withone aspect of the disclosed technology;

FIG. 11 is a rear perspective view of an outdoor power equipmentattachment configured as a snow thrower in accordance with one aspect ofthe disclosed technology;

FIG. 12 is a front perspective view of an outdoor power equipmentattachment configured as a snow thrower in accordance with one aspect ofthe disclosed technology;

FIGS. 13-16 are diagrammatic illustrations showing a methodology forattaching a power unit to an attachment in accordance with one aspect ofthe disclosed technology;

FIG. 17 is a perspective view of a portion of a latching mechanism inaccordance with one aspect of the disclosed technology;

FIG. 18 is a perspective view of a portion of a latching mechanism inaccordance with one aspect of the disclosed technology;

FIG. 19 is a bottom view of a portion of a latching mechanism inaccordance with one aspect of the disclosed technology;

FIG. 20 is an exploded view of a kickstand assembly in accordance withone aspect of the disclosed technology;

FIG. 21 is a top view of a power transfer coupling member in accordancewith one aspect of the disclosed technology;

FIG. 22 is a top perspective view of a power transfer coupling member inaccordance with one aspect of the disclosed technology;

FIG. 23 is a side perspective view of a power transfer coupling memberin accordance with one aspect of the disclosed technology;

FIG. 24 is a bottom perspective view of a power transfer coupling memberin accordance with one aspect of the disclosed technology;

FIG. 25 is a side view of a power transfer coupling member in accordancewith one aspect of the disclosed technology;

FIG. 26 is a top view of a power transfer coupling member in accordancewith one aspect of the disclosed technology;

FIG. 27 is a top perspective view of a power transfer coupling member inaccordance with one aspect of the disclosed technology;

FIG. 28 is a bottom view of a power transfer coupling member inaccordance with one aspect of the disclosed technology;

FIG. 29 is a side view of a power transfer coupling member in accordancewith one aspect of the disclosed technology;

FIG. 30 is a side perspective view of a power transfer coupling memberin accordance with one aspect of the disclosed technology;

FIG. 31 is an exploded view of a power transfer coupling member inaccordance with one aspect of the disclosed technology;

FIG. 32 is a diagrammatic illustration on a power transfer couplingdevice in accordance with one aspect of the disclosed technology;

FIG. 33 is a diagrammatic illustration on a power transfer couplingdevice in accordance with one aspect of the disclosed technology;

FIG. 34 is a cross section of a power transfer coupling device inaccordance with one aspect of the disclosed technology;

FIG. 35 is a cross section of a power transfer coupling device inaccordance with one aspect of the disclosed technology;

FIG. 36 is a cross section of a power transfer coupling device inaccordance with one aspect of the disclosed technology;

FIG. 37 is a cross section of a power transfer coupling device inaccordance with one aspect of the disclosed technology;

FIG. 38 is a diagrammatic illustration of a portion of a power transfercoupling member in accordance with one aspect of the disclosedtechnology;

FIG. 39 is a diagrammatic illustration of a pair of engagement teeth ofa power transfer coupling device in accordance with one aspect of thedisclosed technology;

FIGS. 40-42 are views of an air-cooled power transfer coupling member inaccordance with one aspect of the disclosed technology;

FIG. 43 is a top view of an operator presence actuation member inaccordance with one aspect of the disclosed technology;

FIG. 44 is a side view of an operator presence actuation member inaccordance with one aspect of the disclosed technology;

FIG. 45 is a bottom perspective view of an operator presence actuationmember in accordance with one aspect of the disclosed technology;

FIG. 46 is a top perspective view of an operator presence actuationmember in accordance with one aspect of the disclosed technology;

FIG. 47 is a diagrammatic illustration of a portion of a power unithaving an operator presence actuation member in a non-actuated state inaccordance with one aspect of the disclosed technology;

FIG. 48 is a diagrammatic illustration of a portion of a power unithaving an operator presence actuation member in an actuated state inaccordance with one aspect of the disclosed technology;

FIG. 49 is a diagrammatic illustration of a portion of a snow throwerattachment in accordance with one aspect of the disclosed technology;

FIG. 50 is a cross-sectional view of a snow thrower attachment inaccordance with one aspect of the disclosed technology;

FIG. 51 is a diagrammatic illustration of a snow thrower attachment anda portion of a power unit in accordance with one aspect of the disclosedtechnology;

FIG. 52 is a perspective view of a portion of a power unit in accordancewith one aspect of the disclosed technology;

FIG. 53 is a front view of a portion of a power unit in accordance withone aspect of the disclosed technology;

FIG. 54 is a perspective view of a an outdoor power equipment systemwith a power unit connected to a snow thrower attachment in accordancewith one aspect of the disclosed technology;

FIG. 55 is a rear perspective view of a snow thrower attachment inaccordance with one aspect of the disclosed technology;

FIG. 56 is a perspective view of a an outdoor power equipment systemwith a power unit connected to a lawn mower attachment in accordancewith one aspect of the disclosed technology;

FIG. 57 is a rear perspective view of a lawn mower attachment inaccordance with one aspect of the disclosed technology;

FIG. 58 is a perspective view of a an outdoor power equipment systemwith a power unit connected to a lawn mower attachment including abagging attachment in accordance with one aspect of the disclosedtechnology;

FIG. 59 is a perspective view of a an outdoor power equipment systemwith a power unit connected to a pressure washer attachment inaccordance with one aspect of the disclosed technology;

FIG. 60 is a rear perspective view of a pressure washer attachment inaccordance with one aspect of the disclosed technology;

FIG. 61 is a diagrammatic illustration of a an outdoor power equipmentsystem with a power unit connected to a blower attachment in accordancewith one aspect of the disclosed technology;

FIG. 62 is a rear perspective view of a blower attachment in accordancewith one aspect of the disclosed technology;

FIG. 63 is a diagrammatic illustration of a an outdoor power equipmentsystem with a power unit connected to an electric generator attachmentin accordance with one aspect of the disclosed technology;

FIG. 64 is a sectional view of a portion of a drive assembly for a snowthrower attachment is accordance with one aspect of the disclosedtechnology;

FIG. 65 is a sectional view of a portion of a drive assembly for a powerunit in accordance with one aspect of the disclosed technology;

FIG. 66 is a sectional view of a portion of a drive assembly for ablower attachment is accordance with one aspect of the disclosedtechnology;

It should be noted that all the drawings are diagrammatic and not drawnto scale. Relative dimensions and proportions of parts of these figureshave been shown exaggerated or reduced in size for the sake of clarityand convenience in the drawings. The same reference numbers aregenerally used to refer to corresponding or similar features in thedifferent embodiments. Accordingly, the drawing(s) and description areto be regarded as illustrative in nature and not as restrictive.

DETAILED DESCRIPTION OF EMBODIMENTS

Aspects of the disclosed technology recognize the need for a versatileoutdoor power equipment system in which a common power unit can be usedto releasably attach to a variety of work implements or attachments,where some attachments include and/or require operator presence control,while other attachments do not include and/or require operator presencecontrol. The disclosed technology is directed to a system in which apower unit or cart is configured to include a drive mechanism fordriving attachments that make use of operator presence control (OPC)and/or where OPC is required by industry standards, as well asattachments that do not make use of OPC and/or where OPC is not requiredby industry standards.

Aspects of the disclosed technology also recognize the need for a systemthat is safe, easy to use and intuitive for the user. Aspects of thedisclosed technology further recognize the need for a system in whichalignment and engagement between the power unit and the attachment isstraightforward and reliable.

As is described more fully below, one embodiment of the disclosedtechnology makes use of power transfer coupling device in the form of adog clutch assembly. Many dog clutch designs focus on engagement whilethe dog clutch is moving. Dog clutch designs for engagement while thedog clutch is moving take certain design considerations into account. Ina preferred application of the disclosed technology, the disclosed dogclutch engagement mechanism is configured for engagement when the dogclutch is stationary. The disclosed design also takes into account thatengagement must take place with a limited amount of force between thepower unit and the outdoor power equipment attachment or accessory.

Referring now to FIGS. 1-12, an outdoor power equipment system 10 isprovided. The system 10 includes a power unit (also referred to as abase unit, a base cart or a power cart) 12 and one or more outdoor powerequipment attachments or accessories 14 releasably coupled to the powerunit 12. The power unit 12 includes a frame, housing or other suitablesupport structure (identified generally as 16). The power unit 12includes a power supply 18 (e.g., an engine, such as an internalcombustion engine) operatively coupled to or otherwise supported by theframe 16. In an embodiment where the power supply is an engine, theengine can be configured to be of a similar size and power output asengines typically used in lawn mower and/or snow thrower applications.For example, the engine could be sized between approximate 180 cc and250 cc. Of course, it will be appreciated that other suitable enginescan be employed without departing from the scope of the disclosedtechnology. In accordance with one exemplary embodiment in which theassociated outdoor power equipment attachments include warm weatherattachments, such as a lawn mower, and cold weather attachments, such asa snow thrower, the engine will be configured to operate in bothclimates suitably for powering the respective attachments.

While the power unit 12 is described in conjunction with an engine, itwill be appreciated that other suitable power supply technologies can beemployed without departing from the scope of the disclosed technology.For example, the power unit can include a power supply taking the formof an electric motor operatively coupled to a battery or anothersuitable source of stored energy. In another embodiment, the powersupply may take the form of an electric generator configured to supplymotive force or power to an attachment coupled to the power unit. Thepower unit can include an electric and/or hybrid prime mover withoutdeparting from the scope of the present technology.

The engine 18 or other suitable prime mover is mounted on or otherwisesupported by a frame 16. In the operating position which is shown, forexample, in FIGS. 1-5, the frame is configured to support the engine 18in an orientation approximately parallel to the ground when the powerunit is in its normal operating position. Wheels 20 are rotatablymounted or otherwise operatively coupled to the frame, and the wheelsare used for moving the power unit. In one embodiment, the power unit 12includes driven wheels operatively coupled to a drive system such thatthe power unit is self-propelled in response to user control.Alternatively, the power unit can be implemented without aself-propelled feature. The wheels can be of a common size and treaddesign selected to accommodate the numerous configurations of accessoryused in connection with the power unit. It will be appreciated that thewheels can take on a number of suitable configurations without departingfrom the scope of the disclosed technology.

The engine can be configured as a two-stroke or four-stroke internalcombustion engine of the type generally known in the art and suitablefor use in powering lawn and garden equipment. In the disclosedembodiment, the engine is configured for operation in warm conditionsand cold conditions (e.g., an all-season or all-weather engine). In apreferred embodiment, the engine is operatively coupled to a generallyhorizontal drive shaft for use in powering the associated outdoor powerequipment attachments through a suitable coupling member also referredto as a power takeoff coupling member or a power transfer couplingmember (identified generally as 22) in the manner described more fullybelow.

The power unit 12 includes a handle portion 24 equipped with suitableuser controls (identified generally as 26), including an operatorpresence control member 28 (e.g., a bail, lever or other appropriatecontrol mechanism). In one embodiment, the handle portion 24 isconfigured to include a single substantially continuous handle memberthat supports plurality of user controls. Alternatively, as shown inFIG. 2, the handle portion 26 can be configured to include separatehandle members 30, 32 with one or both of the handle members havingassociated user controls 26. In the embodiment illustrated in FIG. 2,the handle portion include separate handle members 30, 32 with one ofthe handle members 30 including an operator presence control member 28in the form of a lever pivotally connected to the first handle member30. As is described more fully below, the operator presence controlmember can be selectively activated by the user to activate anddeactivate an operator presence actuation member.

In accordance with one embodiment, the power unit 12 can include akickstand 34 or other suitable support to support the power unit frameor housing approximately parallel to the ground when the power unit 12is not coupled to an attachment or accessory. As is described below inmore detail, the kickstand 34 can be used to actuate a latchingmechanism when an attachment or accessory is connected and/ordisconnected to the power unit.

The user controls 26 can include controls for turning the engine on andoff, operating the rotation of the wheels, the braking of the wheels,and/or other suitable user control functions. In one embodiment, theuser applies manual forward force to the handle portion to move thepower unit. In another embodiment, the engine is configured to power thewheels. For example, the engine can be connected to a wheel transmissionfor rotating the wheels at various speeds, and a wheel speed control onthe control panel can be used for this purpose. In the embodimentillustrated in FIG. 2, the power unit 12 includes a wheel speed controllever 36 that controls the forward drive speed of the wheels on thepower unit. In an alternative embodiment, the wheel control can providea forward, neutral and possibly backward movement of the wheels. Theengine can be started by either a pull start or an electric starterconnected to a battery, as is known in the art.

In a preferred embodiment, the engine is operatively coupled to a driveshaft and configured to supply rotational movement to the drive shaftoriented in the horizontal direction. As is discussed more fully below,the drive shaft is attached to a coupling device (also referred to as apower transfer coupling device or member).

As is discussed more fully below, the power unit 12 is configured toinclude an engagement and alignment attachment mechanism (indicatedgenerally as 40) for quickly and easily attaching the power unit 12 to aselected outdoor power equipment accessory 14. The attachment oraccessory 14 includes an engagement and alignment mechanism 42configured to cooperate with the engagement and alignment mechanism 40associated with the power unit 12 such that the power unit can bequickly and easily coupled or releasably coupled to the accessory. Itwill be appreciated that the attachment and alignment mechanismsassociated with the power unit 12 and the attachment or accessory 14 cantake on a variety of forms and configurations without departing from thescope of the disclosed technology. For example, in accordance oneexemplary embodiment, the power unit 12 can include a horizontal rod orbar oriented transversely across the front of the unit or a portion ofthe front of the unit, while the associated attachment can include oneor more hook elements or recesses positioned and configured to receivethe rod when the power unit is coupled to the outdoor power equipmentaccessory.

FIG. 5 and FIG. 1 illustrate an exemplary embodiment in which the powerunit 12 includes a horizontally-oriented rod (also referred to as ahorizontal engagement member or bar) 40 positioned above and extendingforward of the substantially flat front surface of the front attachmentplate 44. The rod 40 is centrally positioned relative to the lateraldimension of the power unit 12. FIG. 11 illustrates an exemplary snowthrower attachment 14 that includes a corresponding engagement member 42sized and positioned to receive the horizontal rod 40 coupled to thepower unit 12. In the illustrated exemplary embodiment, the engagementmember 42 coupled to the attachment includes or otherwise defines arecess sized to receive the horizontal engagement member coupled to thepower unit.

Referring now to FIGS. 13-16, in operation, the user will move the powerunit in proximity to the desired outdoor power equipment attachment(e.g., a snow thrower attachment or a lawnmower attachment). The userwill engage or otherwise couple the power unit to the accessory bylowering the front end of the power unit such that the horizontalengagement member or bar 40 is vertically lower than the correspondingengagement member or hook or recess 42 on the accessory (thecontrol/handle portion will raise up relative to the user), asillustrated in FIG. 13.

The user then positions the engagement and alignment member on the powerunit below the engagement and alignment member on the attachment androcks or otherwise pivots the front end of the cart up by pushing downon the control/handle portion, as illustrated in FIGS. 14-16. Inaccordance with one exemplary embodiment, the power unit includes one ormore latching members (e.g., disposed near the bottom of the frontportion of the power unit). The outdoor power equipment accessory orattachment includes slots, catches, strikers or other suitable receiversor latching members configured to receive the latching members when thepower unit is coupled to the accessory.

As described more fully below, the power unit can be configured toinclude a locking member configured to be operated by the user to lockthe latching members in place upon receipt of the latching members intothe receiving slots or catches on the attachment. The latching memberscan be configured as pawls or any other suitable hook or latchingmember.

It will be appreciated that this system and method of engagement allowsfor reliable and intuitive alignment and engagement between the powerunit and the associated attachment, as well as a secure interfacebetween the power unit and the attachment.

Turning now to FIGS. 17-20, an exemplary latching mechanism (identifiedgenerally as 45) will be described. In the illustrated embodiment, thelatching mechanism 45 includes a rotatable support (e.g., a kickstand)34 rotatably coupled to a rear portion of the power unit. The kickstand34 can be rotated between an upward position in which the kickstand isin a substantially horizontal orientation and a downward position inwhich the kickstand is in a generally vertical orientation (e.g., at anangle of about 10 degrees to about 20 degrees to a vertical direction).In the downward position, the kickstand 34 serves to balance and supportthe power unit so that the power unit does not tip forward or backwardwhen the power unit is not attached to an associated attachment oraccessory.

The kickstand 34 is connected to a cable 46 or other suitable forcetransfer member. The cable 46 is connected to one or more latch members47 positioned adjacent a front portion of the power unit. In theillustrated embodiment, the front attachment plate defines a pair ofopenings 48 adjacent a lower portion of the front attachment plate 44.The latch members 47 or hooks are positioned within those openings 48.In the illustrated embodiment, the cable 46 is coupled to a rod 49, andthe rod 49 is coupled to a pair of latch members 47 or hooks. The rod 49is rotatable between a latched positioned in which the rod 49 is rotatedforward such that the latch members 47 are in an engaging or latchingposition, and a released position in which it is rotated backward. As isshown in FIG. 17, the rod 49 is spring-biased such that the latchmembers 47 default to a forwardly-rotated engaging or latching position.

In the illustrated embodiment, the associated attachment includes a pairof strikers 51 or catches extending from a back attachment plate of theattachment. The strikers 51 are sized and positioned such that the latchmembers 47 engage the strikers when the attachment is properlypositioned in front of and abutting the power unit. The openings 48 inthe front attachment plate 44 are sized and positioned to receive thestrikers 51 when the attachment is attached to the power unit.

In the illustrated embodiment, the power unit further includes a switch53 (e.g., a plunger switch) extending from the front attachment plate ofthe power unit. When an attachment is properly positioned and attachedto the power unit, the attachment depresses or otherwise activates theswitch 53 such that the power supply (e.g., an engine) can be started orotherwise activated.

When the user is ready to detach the attachment from the power unit, thekickstand 34 can be rotated into its upward position. Rotation of thekickstand 34 into its upward position pulls on the cable 46, which, inturn, rotates the rod 49 and latch members 47 in the releasedpositioned, whereby they release the strikers 51. The user can tip thefront end of the power unit slightly down to detach the power unit fromthe attachment.

Turning now to FIGS. 21-25, as is discussed above, the power unit 12includes a power transfer coupling device (also referred to as a powertakeoff coupling device, a power transfer device or simply as a dogclutch) 22. In accordance with one exemplary embodiment, the powertransfer coupling device 22 includes a base 50, such as a round base,and a plurality of teeth or engagement members (also referred to asengagement teeth) 52 extending up or away from the base. In accordancewith one exemplary embodiment, the teeth 52 each include a lower portion54 having a pair of sidewalls 56, an outer wall 58, and an inner wall 60extending up or away from the base 50 and a top portion including a pairof top walls or angled walls 62 that extend from the sidewalls 56 andmeet forming an angle.

In accordance with one exemplary embodiment, the engagement teethinclude substantially parallel sidewalls with a triangular top portionextending from the sidewalls and forming an angle. In accordance withone exemplary embodiment, the angle varies across the dimension of thetooth. For example, in accordance with one exemplary embodiment, theangle formed by top walls of the triangular top portion is greater atthe outer edge or wall of the tooth than it is at the inner edge or wallof the tooth. In accordance with another exemplary embodiment, the angleformed by the top walls is approximately the same at the outer wall andat the inner wall.

In accordance with one exemplary embodiment, the top walls of thetriangular top portion of each engagement tooth form an angle ofapproximately 50 degrees to approximately 90 degrees. In anotherexemplary embodiment, the top walls of the triangular top portion ofeach engagement tooth form an angle of approximately 60 degrees toapproximately 80 degrees. In accordance with another exemplaryembodiment, the top walls of the triangular top portion of eachengagement tooth form an angle of about 45 degrees to about 75 degrees.In yet another exemplary embodiment, the top walls of the triangular topportion of each engagement tooth form a substantially constant anglefrom the outer wall to the inner wall (e.g., an angle of approximately90 degrees). It will be appreciated that the triangular top portion ofthe engagement teeth can take on other angles and angular ranges withoutdeparting from the scope of the disclosed technology.

It will be appreciated that the base can take on any dimensions suitablefor a particular application. For example, in accordance with oneexemplary embodiment, the base of the power transfer coupling member hasa diameter of approximately 3 inches to approximately 5 inches. Inaccordance with another embodiment, the base of the power transfercoupling member has a diameter of about 4 inches to about 6 inches. Itwill be appreciated that the power transfer coupling member can be madeof any suitable material, such as nylon or aluminum. Preferably, thepower transfer coupling member is a solid piece. Alternatively, thepower transfer coupling member could be hollow or semi-solid.

In accordance with one embodiment, the power transfer coupling memberassociated with the power unit can be made of a different material thanthe power transfer coupling member associated with the attachment oraccessory (e.g., the power transfer coupling member associated with thepower unit can be made of aluminum, powdered metal or another suitablemetal, while the power transfer coupling member associated with theattachment can be made of nylon or another suitable non-metal material).In an alternative embodiment, the first and second power transfercoupling members can be made of the same material.

Turning now to FIGS. 26-31, an alternative exemplary embodiment of apower transfer coupling member 23 (e.g., a power transfer couplingmember associated with an attachment or accessory) is illustrated. Inone exemplary embodiment, the power transfer coupling assembly caninclude a first power transfer coupling member (e.g., the power transfercoupling member 22 illustrated in FIGS. 21-25) and a second powertransfer coupling member 23 (e.g., the power transfer coupling memberillustrated in FIGS. 26-31). In the illustrated exemplary embodiment,the power transfer coupling member 23 can include one or more vibrationdamping members (also referred to as bumpers or noise dampers) 55disposed between the first and second power transfer coupling members.It will be appreciated that the provision of vibration damping members55 serves to reduce vibration in the system as well as associated noiseotherwise generated by the power transfer coupling member. FIGS. 26-31illustrate an exemplary embodiment in which the power transfer couplingmember 23 associated with the attachment or accessory includes aplurality of bumpers or vibration damping members 55. In the illustratedembodiment a plurality of the engagement teeth associated with the powertransfer coupling member 23 include or otherwise define recesses 57 thatreceive vibration damping members 55. The vibration damping members 55can be made of any suitable material, including, but not limited tonylon and rubber. It will be appreciated that one or both of the powertransfer coupling members can include one or more vibration dampingmembers without departing from the scope of the disclosed technology.

It will be appreciated that aspects of the disclosed technologyrecognize and solve the problem of engaging a power unit to anattachment through a power transfer coupling member that is stationaryduring engagement. In this environment, the device has only the weightof the attachment being coupled to the power unit to provide an opposingforce to ensure engagement of the power transfer coupling member withits mating power transfer coupling member associated with theattachment.

Further, it will be appreciated that the configuration of the engagementteeth, including the triangular top portion of the engagement teeth andthe sidewall geometry of the engagement teeth, allows for easy andreliable mating between the power takeoff coupling member associatedwith the power unit and the power takeoff coupling member associatedwith the attachment, even if the engagement teeth are somewhatmisaligned upon coupling of the attachment to the power unit.

In accordance with one exemplary embodiment, the power transfer couplingmembers associated with the power unit and the attachment aresubstantially the same or identical. It will be appreciated, however,that the respective power transfer coupling members associated with thepower unit and the attachment do not have to be the same. For example,the power transfer coupling member associated with the power unit caninclude engagement teeth of a different size and/or geometry incomparison to the engagement teeth of the power transfer coupling unitassociated with the attachment.

As another example, the power transfer coupling member associated withthe power unit could be configured to have 12 engagement teethpositioned about the perimeter of the base at approximately every 30degrees, while the power transfer coupling member associated with theattachment could have 6 engagement teeth positioned about the perimeterof the base at an angle of approximately 60 degrees between respectiveengagement teeth. Also, while the power transfer coupling member isillustrated with substantially constant spacing between adjacentengagement teeth, it will be appreciated that the power transfercoupling unit may include variable spacing between adjacent engagementteeth without departing from the scope of the disclosed technology.

It will be appreciated that the configuration of the power transfercoupling member provides easy and reliable engagement of the two halvesof the power transfer coupling member using the angled attachmentmethodology between the power unit and the attachment described morefully above with reference to FIGS. 13-16.

FIGS. 32-37 illustrate exemplary embodiments in which the power transfercoupling member associated with the power unit engages the powertransfer coupling member associated with the attachment. FIG. 34 andFIG. 36 show an exemplary situation in which the two halves of the powertransfer coupling device or dog clutch are completely aligned axially,such that the engagement teeth engage each other on the outer edge ofthe tooth sidewalls (near the outer diameter of the power transfercoupling device). It will be appreciated that this provides a preferredengagement at the outer portion of each tooth since the tooth is widernear the outer diameter of the power transfer coupling member, and therequired force to transmit a given torque is less at this outerlocation.

The design of the power transfer coupling member addresses the problemof misalignment of the two halves of the power transfer coupling memberor dog clutch. As shown in FIG. 35, even with 0.050 inches ofmisalignment upon coupling the power unit to the attachment, the teethstill engage on or adjacent the outer edge, to provide preferred torquetransfer.

As noted above, the disclosed technology recognizes and solves theproblem associated with reliably and smoothly coupling a power unit toan attachment where misalignment of the two halves of the power transfercoupling device can occur frequently. In the case of such misalignmentbetween the two halves of the power transfer coupling member, engagementcould occur near the inner portion of the engagement teeth (close to theinner diameter or inner wall of the engagement teeth), where the teethare thinner and where greater force is required to transmit a giventorque. This scenario is illustrated in FIG. 37.

The power transfer coupling device design of the disclosed technologyrecognizes and solves this problem to achieve a consistent engagementarea. The power transfer coupling design of the disclosed technologyaccomplishes this with the geometry of the engagement teeth. As can beseen in FIG. 38, the sidewalls of the engagement teeth are positionedand oriented at angles that do not converge on the rotational center ofthe power transfer coupling device. Rather, the engagement teeth areconfigured such that the tooth sidewalls are angled to meet at a pointbetween the engagement tooth and the center of the power transfercoupling device. This configuration and offset allows the teeth toengage consistently (as described above) up to a predetermined maximumexpected misalignment of the two halves of the power transfer couplingdevice.

Once the attachment has been coupled to the power unit, and therespective halves of the power transfer coupling member have engaged oneanother, the power unit will rotationally drive the first part of thepower transfer coupling member associated with the power unit, which, inturn, will cause rotation of the second part of the power transfercoupling member associated with the attachment. In addition to providingreliable engagement, even in the case of misalignment, it will beappreciated that the engagement teeth geometry has been designed tominimize forces that would act to push apart the two halves of the powertransfer coupling member while the power transfer coupling member isbeing driven. For example, in accordance with one exemplary embodiment,each engagement tooth can be thought of as having a top third, a middlethird, and a bottom third. When the engagement teeth of the respectiveparts of the power transfer coupling member are engaged, the teeth aredesigned such that the middle portions of adjacent engagement teeth meshtogether and align in a manner that resists pushing apart while thepower unit is driving the attachment (see FIG. 39).

It will be appreciated that the power transfer coupling member may havea larger or smaller number of teeth than what is illustrated in FIGS.21-25 and FIGS. 26-31. For example, each or one part of the powertransfer coupling member may have between 6 engagement teeth and 12engagement teeth. Alternatively, the power transfer coupling device canbe configured such that each part or at least one part of the powertransfer coupling device has greater than 12 engagement teeth.Alternatively, the power transfer coupling device can be configured suchthat each part or at least one part of the power transfer couplingdevice has less than 6 engagement teeth.

It will be appreciated that the power transfer coupling member or dogclutch can include other features or geometries depending upon aparticular application. For example, in accordance with one application,the power transfer coupling member can be configured to include integralcooling elements, such as the fins or fan blades shown in FIGS. 40-42.This configuration can provide cooling through airflow while the powertransfer coupling device rotates.

Referring now to FIGS. 43-46, in addition to a power transfer couplingdevice 22 (described above), the power unit 12 is equipped with anoperator presence actuation member (also referred to simply as anattachment actuation member) 80. In accordance with one embodiment, theoperator presence actuation member 80 is configured to rotate inresponse to user actuation of an operator presence control (e.g., lever28 or a bail) disposed on the handle portion of the power unit. Theoperator presence control on the handle is coupled to the operatorpresence actuation member 80 such that user operation of the operatorpresence control causes rotational motion of the operator presenceactuation member 80. This rotational motion, in turn, is transferredacross the interface between the power unit and the attachment such thatpower from the power unit is operatively coupled and transferred to theworking member of the given attachment. While the operator presenceactuation member 80 is being described in connection with a rotationalactuation member, it will be appreciated that the operator presenceactuation member can be configured as a slider or other translationalmember without departing from the scope of the disclosed technology.

In accordance with one exemplary embodiment, the operator presenceactuation member 80 takes the form of a rotatable member having at leasta pair of protrusions or lugs 82, while the mating operator presenceactuation member associated with the attachment (identified generally as90) includes at least a pair of recesses or slots positioned andconfigured to receive the protrusions or lugs 82 from the operatorpresence actuation member 80 associated with the power unit. While theoperator presence actuation member 80 is shown having a pair ofprotrusions or lugs 82, it will be appreciated that other geometries andconfigurations may be employed without departing from the scope of thedisclosed technology. For example, the operator presence actuationmember can be configured to include three protrusions or lugs, fourprotrusions or lugs, or another set of engagement features withoutdeparting from the scope of the disclosed technology. Alternatively, theoperator presence actuation member associate with the attachment can beconfigured to include protrusions or lugs, while the operator presenceactuation member associate with the power unit can be configured toinclude recesses or slots positioned and configured to receive theprotrusions or lugs from the operator presence actuation memberassociated with the attachment.

In accordance with one exemplary embodiment, movement of the operatorpresence control by the operator (e.g., movement of the lever 28)operates an actuation cable or other transfer device coupled to thelever, the distal end of the actuation cable being attached to theoperator presence actuation member, such that movement of the bale bythe operator causes rotational movement of the operator presenceactuation member associated with the power unit. FIG. 47 and FIG. 48illustrate a portion of an exemplary assembly, where a front portion ofthe power unit is removed to show rotation of a portion of the operatorpresence actuation member 80 associated with the power unit. FIG. 47shows a situation where the operator presence control is not actuated bythe operator, and the operator presence actuation member 80 is in itsdefault state (indicating that an OPC-enabled attachment should not beactuated. In contrast, FIG. 48 shows a situation in which the operatorhas engaged the operator control (e.g., by squeezing or otherwise movingthe lever 28), which, in turn, causes rotation of the operator presenceactuation member 80, actuating the OPC-enabled attachment coupled to thepower unit. In the illustrated embodiment, the operator presenceactuation member is biased in the non-actuated position, for example,using a spring or other biasing member.

This rotational movement of the operator presence actuation member 80associated with the power unit 12 is transferred across the interface tothe operator presence actuation member 90 associated with the attachment14, which, in turn, causes the power transfer coupling member associatedwith the attachment to be in operative engagement with the workingmember 92 associated with the attachment. It will be appreciated that avariety of mechanisms can be used to place the power transfer couplingmember associated with an attachment in operative engagement with theworking member 92 associate with the particular attachment. For example,the embodiment of FIGS. 49-51 illustrates an exemplary snow throwerattachment.

In the exemplary snow thrower embodiment, the power transfer couplingmember is coupled to a first pulley 94 within the snow throwerattachment. The snow thrower attachment also includes a second pulley 96(e.g., a pulley of a larger diameter) with a belt 98 being operativelycoupled to both pulleys. When the operator presence actuation member 90is not in the actuated position, the belt 98 between the two pulleys isnot tensioned, and the belt 98 is kept off or otherwise does not engagein a manner to cause rotation of the first pulley 94, while the pulleyassociated with the power transfer coupling member is being rotated.Upon actuation of the operator presence actuation member 90, the belt 98is tensioned, for example using a tensioner pulley 80 such that themotive power from the first pulley 94 is transferred to the secondpulley 96 to operate the working member 92, in this case, augers and animpeller associated with an exemplary two-stage snow thrower attachment.It will be appreciate that other mechanisms can be employed to place thepower transfer coupling member associated with an attachment inoperative engagement with the working member 92 associate with theparticular attachment without departing from the scope of the disclosedtechnology.

In accordance with one preferred embodiment, the power unit is operatedsuch that the power takeoff associated with the power unit is operatedat a constant speed. Stated differently, the engine or other source ofmotive power rotates the drive shaft of the power unit at a constantspeed, and any necessary gear reduction or speed modification associatedwith the needs of a particular attachment is accomplished on theattachment itself. For example in the embodiment illustrated in FIG. 49,this is done using pulleys of different sizes such that the speed atwhich the drive shaft is rotated is slowed down in accordance with theneeds of a snow thrower application. For example, the drive shaftassociated with the power unit may be rotated at approximately 3600revolutions per minute, while a typical snow thrower application mayrequire a drive speed of approximately 1,150 revolutions per minute. Inanother exemplary embodiment, necessary gear reduction can beaccomplished using a suitable gear set, for example, gears disposedwithin a gear box associated with the attachment.

It will be appreciated that some outdoor power equipment attachmentsmake use of or otherwise require operator presence control, such as alawn mower or a snow thrower, while other outdoor power equipmentattachments do not require operator presence control to be compliantwith normal specifications and operating safety standards. Examples ofoutdoor power equipment attachments that do not typically make use ofoperator presence control include generators and pressure washers. Inthe case of attachments that do not make use of operator presencecontrol, the attachment will be configured to automatically actuate theoperator presence actuation member upon secure connection of theattachment to the power unit, for example, in the manner described abovewith reference to FIGS. 13-19.

FIGS. 52-53 illustrate another exemplary embodiment in which the powerunit 12 is configured to operate both operator presence controlledattachments as well as non-operator presence controlled attachments. Inthis alternative exemplary embodiment, the power unit is configured toinclude a pair of power transfer coupling members (illustrated in FIGS.52-53 as a pair of dog clutch members having the general design andspecifications described more fully above) 110, 112. In this exemplaryembodiment, the engine is operatively coupled to the first powertransfer coupling member 110 and selectively coupled to the second powertransfer coupling member 112.

In one embodiment, the first power transfer coupling member 110 is adirect drive coupling member such that the power transfer couplingmember rotates once the power unit is powered up. In this exemplaryembodiment, the second power transfer coupling member 112 is a clutcheddrive member, or otherwise selectively engaged drive member, such thatthis power transfer coupling member will only rotate upon actuation ofan operator presence control by the user of the power unit. Thisclutched drive of the second power actuation member can be accomplishedusing a number of configurations, such as making use of a tensionerinside the housing of the power unit, where such tensioner tensions abelt between the drive shaft of the engine and the second power transfercoupling member upon actuation of the operator presence control by theuser of the power unit.

It will be appreciated that the power unit and attachment systemdescribed above provides great versatility in terms of using a commonpower unit to operate both operator presence controlled attachments aswell as attachments that do not make use of operator presence control.This is accomplished in a smooth and seamless manner that is transparentto and easy for the user. It will be further appreciated that thefeatures of the disclosed technology allow the attachment engagementprocess to be easy and intuitive for the user, such that it can beaccomplished in a matter of several seconds.

It will be appreciated that the system described above can be used inconnection with a large number of different attachment configurations,including, but not limited to a snow thrower configuration (FIGS.54-55), a lawnmower configuration (FIGS. 56-58), a generatorconfiguration (FIG. 63), a power washer configuration (FIGS. 59-60), ablower configuration (FIGS. 61-62), a trimmer configuration, a waterpump configuration, a tiller configuration, an aerator configuration,etc.

While aspects of the disclosed technology have been described withrespect to outdoor power equipment applications, it will be appreciatedthat the disclosed technology may be employed in connection with otherapplications. For example, aspects of the disclosed technology may findapplication in connection with an indoor power system in which a commonmotor on a power unit can be releasably coupled to a number of indoorwork tools.

Although the disclosed technology has been shown and described withrespect to a certain preferred aspect, embodiment or embodiments, it isobvious that equivalent alterations and modifications will occur toothers skilled in the art upon the reading and understanding of thisspecification and the annexed drawings. In particular regard to thevarious functions performed by the above described elements (components,assemblies, devices, members, compositions, etc.), the terms (includinga reference to a “means”) used to describe such elements are intended tocorrespond, unless otherwise indicated, to any element which performsthe specified function of the described element (i.e., that isfunctionally equivalent), even though not structurally equivalent to thedisclosed structure which performs the function in the hereinillustrated exemplary aspect, embodiment or embodiments of the disclosedtechnology. In addition, while a particular feature of the disclosedtechnology may have been described above with respect to only one ormore of several illustrated aspects or embodiments, such feature may becombined with one or more other features of the other embodiments, asmay be desired and advantageous for any given or particular application.

What is claimed is:
 1. A power transfer coupling device configured tocouple a base power unit to an outdoor power equipment accessory, thepower transfer coupling device comprising: a base; a plurality ofengagement teeth extending from the base, each of the plurality ofengagement teeth having a lower portion including a pair of side walls,an outer wall, and an inner wall disposed radially inward from the outerwall, and a top portion have a pair of top walls that extend from theside walls and meet at an angle.
 2. The power transfer coupling deviceof claim 1, wherein the angle formed by the top walls is greater at theouter wall than at the inner wall.
 3. The power transfer coupling deviceof claim 1, wherein the angle formed by the top walls is approximatelythe same at the outer wall and at the inner wall.
 4. The power transfercoupling device of claim 1, wherein the engagement teeth are positionedabout a perimeter of the base.
 5. The power transfer coupling device ofclaim 1, wherein the engagement teeth are positioned about the perimeterof the base with approximately equal spacing between adjacent engagementteeth.
 6. The power transfer coupling device of claim 1, wherein theengagement teeth are positioned about the perimeter of the base withvariable spacing between the engagement teeth.
 7. The power transfercoupling device of claim 1, wherein the base is round.
 8. The powertransfer coupling device of claim 1, wherein the angle formed by the topwalls is between about 90 degrees and about 50 degrees.
 9. The powertransfer coupling device of claim 1, wherein the angle formed by the topwalls is between about 80 degrees and about 60 degrees.
 10. The powertransfer coupling device of claim 1, wherein the angle formed by the topwalls varies from about 75 degrees to about 45 degrees.
 11. The powertransfer coupling device of claim 1, wherein the device includes 12engagement teeth.
 12. The power transfer coupling device of claim 1,wherein the device includes at least 6 engagement teeth.
 13. The powertransfer coupling device of claim 1, wherein the device includes no morethan 6 engagement teeth.
 14. The power transfer coupling device of claim1, wherein the base is round with a diameter of about 3 inches to about5 inches.
 15. The power transfer coupling device of claim 1, wherein thebase is round with a diameter of about 4 inches to about 6 inches.
 16. Adog clutch assembly configured to rotationally transfer power from abase power unit to an outdoor power equipment attachment releasablycoupled to the base power unit, the dog clutch assembly comprising: afirst member, the first member comprising a base and a plurality ofengagement teeth extending from the base, each of the plurality ofengagement teeth having a lower portion including a pair of side walls,an outer wall, and an inner wall, and a top portion have a pair of topwalls that extend from the side walls and meet at an angle; and a secondmember, the second member comprising a base and a plurality ofengagement teeth extending from the base, each of the plurality ofengagement teeth having a lower portion including a pair of side walls,an outer wall, and an inner wall, and a top portion have a pair of topwalls that extend from the side walls and meet at an angle; wherein thefirst member and second member are configured to engage one another byway of the engagement teeth associated with the first member and thesecond member.
 17. The dog clutch assembly of claim 16, wherein thefirst member and the second member are substantially identical.
 18. Thedog clutch assembly of claim 16, wherein the second member includes oneor more vibration damping members.
 19. The dog clutch assembly of claim18, wherein the one or more vibration damping members are positionedwithin one or more recesses formed in one or more of the engagementteeth.
 20. The dog clutch assembly of claim 16, wherein the first memberand the second member include the same number of engagement teeth. 21.The dog clutch assembly of claim 16, wherein the first member and thesecond member have a different number of engagement teeth.
 22. The dogclutch assembly of claim 16, wherein the angle formed by the top wallsof the first member is greater at the outer wall than at the inner wall.23. The dog clutch assembly of claim 16, wherein the angle formed by thetop walls of the second member is approximately the same at the outerwall and at the inner wall.
 24. A power transfer coupling deviceconfigured to couple a base power unit to an outdoor power equipmentaccessory, the power transfer coupling device comprising: a base; aplurality of engagement teeth extending from the base, each of theplurality of engagement teeth having a lower portion including a pair ofside surface, an outer surface, and an inner surface disposed radiallyinward from the outer surface, and a top portion have a pair of topsurfaces that extend from the side surfaces and meet at an angle. 25.The power transfer coupling device of claim 24, wherein the angle formedby the top surfaces is greater at the outer surface than at the innersurface.
 26. The power transfer coupling device of claim 24, wherein theangle formed by the top surfaces is approximately the same at the outersurface and at the inner surface.